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HYPERTENSION ? Hypertension (high blood pressure) is a common condition that can lead to serious complications if left untreated. Studies suggest that a person's diet and weight play an important role in the onset and persistence of hypertension, and that simple dietary changes and weight loss are effective measures for reducing blood pressure.

Dietary changes and weight loss are called nonpharmacologic measures, that is, measures that do not involve drugs. Other nonpharmacologic measures for controlling blood pressure and its associated risks include smoking cessation, stress reduction, and regular exercise. These different types of nonpharmacologic measures are effective individually, but often have the greatest benefit when used together.

Nonpharmacologic measures can improve the effectiveness of antihypertensive drugs and may even eliminate the need for drugs. These measures also have other benefits: they have few or no side effects, they reduce a person's overall risk of cardiovascular disease, and, if started early, they may even prevent hypertension in people who are at risk for this condition.

It is important to work with your doctor to develop a reasonable, well-rounded treatment plan for hypertension. Nonpharmacologic measures entail lifestyle adjustments that can be difficult to initiate and maintain, but your doctor can provide guidelines to ease these adjustments and can help you track your progress over time.

DIETARY CHANGES AND BLOOD PRESSURE ? Research has shown that dietary factors affect blood pressure and that dietary changes are an effective approach for controlling hypertension and possibly even preventing this condition.

Dietary changes usually begin with an evaluation of a person's current diet, cooking habits, and eating habits. After specific dietary patterns are identified, a person can learn strategies for altering the amounts of specific nutrients in his or her diet.

Reducing sodium intake ? Sodium makes up 40 percent of table salt so that 3000 mg of salt (about one level teaspoon or three packets of salt) contain 1200 mg of sodium, which is the ingredient listed on the label of all processed food. Most fresh foods have a low sodium content, but sodium is often added during food and beverage processing. In the American diet, this added sodium accounts for about 80 percent of a person's total sodium intake.

Several lines of evidence strongly link a high sodium intake to hypertension. As an example, hypertension rarely occurs in countries in which people consume less than 1000 mg per day of sodium; it primarily occurs in countries in which people consume more than 2000 mg of sodium per day. Most Americans consume about 4000 milligrams of sodium per day.

One study found that, compared to adolescents who were fed a standard diet in infancy, adolescents who were fed a low-salt diet in infancy had a lower blood pressure. Other studies have shown that reducing sodium intake lowers blood pressure both in people with hypertension and in people with borderline high blood pressure. Reducing sodium intake has also decreases the likelihood that hypertension will return in people who stop taking antihypertensive drugs.

Switching from a higher sodium diet to a lower sodium diet has also been associated with a slight reduction in blood pressure in people with normal blood pressure. When people with normal blood pressure reduce their sodium intake from 4000 mg to 2000 mg per day, their blood pressure falls by 2 to 3 mmHg; over several years, the reduction may be as great as 10 mmHg. The benefit of this reduction may be a substantially lower risk of cardiovascular disease.

Added benefits of reducing sodium intake ? In addition to directly reducing blood pressure, a lower sodium intake may also enhance the effectiveness of antihypertensive drugs and the effectiveness of other nonpharmacologic measures such as weight loss. A lower sodium intake has also been associated with other health benefits, including a reduced risk of dying from a stroke, a reversal of heart enlargement, and a reduced risk of kidney stones and osteoporosis.

Sodium sensitivity ? For unknown reasons, some people have more marked blood pressure responses to changes in dietary sodium than other people. This condition is called sodium sensitivity. Sodium sensitivity is more common with increasing age and more common among black individuals, obese individuals, and individuals with impaired kidney function. Cardiovascular events, such as heart attacks, are more common in people who have sodium sensitivity.

Guidelines for reducing sodium intake ? Several professional organizations have issued guidelines for reducing sodium intakes. The guidelines recommend that people with an elevated blood pressure consume no more than 2400 milligrams of sodium or 6 grams of salt per day. The sodium content of packaged, processed, and prepared foods can usually be determined by reading food labels.

It is often difficult to abruptly cut back on the amount of sodium in the diet, but most people find that they do not miss the sodium if they cut back gradually. The full benefits of a lower sodium diet on blood pressure may not be evident for at least six weeks.

Possible side effects of reducing sodium intake ? Some studies have noted possible side effects associated with a very low sodium diet. However, a moderate reduction in dietary sodium to the level of 2000 milligrams per day is a safe and effective approach for controlling blood pressure.

Reducing alcohol intake ? There is a clear association between excess alcohol intake and the development of hypertension. People who have more than two drinks per day have a one- to two-fold increase in the incidence of hypertension compared to nondrinkers; this effect is dose-related and is most prominent when intake exceeds five drinks per day. On the other hand, alcohol intake below two drinks per day appears to have a cardioprotective effect (benefits the heart), even in patients with preexisting hypertension.

Maintaining a vegetarian diet ? Maintaining a vegetarian diet may reduce elevated blood pressure and protect against the onset of hypertension. One study found that people with mild hypertension have a lower systolic blood pressure (the top number of the blood pressure reading) when they ate a vegetarian diet than when they ate a standard diet.

It is unknown why a vegetarian diet may reduce blood pressure, but the effect may be related to the lower protein content or higher fiber content of vegetarian diets relative to standard diets. The specific effects of fiber intake on blood pressure are still uncertain. One study found that diastolic blood pressure (the bottom number of the blood pressure reading) fell by an average of 4 mmHg in people who ate a high-fiber diet.

Moreover, high-fiber diets may have other health benefits, including lower total cholesterol levels and lower insulin levels. A strict vegetarian diet may not be necessary to obtain the associated health benefits: one study suggested that some components of a vegetarian diet, such as fruits and vegetables, as well as low-fat dairy products, and a low saturated and total fat intake lower blood pressure when incorporated into a non-vegetarian diet.

Reducing caffeine intake ? Caffeine causes a rise in blood pressure and can worsen the rise in blood pressure triggered by stress. However, this rise in blood pressure is transient because the body compensates for the effects of caffeine. Moderate caffeine consumption has not been associated with an increased risk of hypertension in most people. However, the chronic consumption of large amounts of caffeine (an average of five cups of coffee per day) is associated with small increases in blood pressure in some people; this effect may be especially pronounced in older adults with hypertension. Therefore, reducing caffeine intake may lower blood pressure in some people.

WEIGHT LOSS AND BLOOD PRESSURE ? Excess body weight is associated with a higher risk of hypertension and adds to the risk of cardiovascular disease associated with hypertension. People with high blood pressure are more likely to be overweight than people with normal blood pressure. Gradual weight gain throughout life appears to contribute to the increase in blood pressure associated with aging.

Weight loss can be achieved by a sensible program that entails reducing the number of calories in a diet, increasing physical activity, or best of all, a combination of these measures.

Benefits of weight loss on blood pressure ? Long-standing obesity raises blood pressure and makes hypertension more difficult to control; in contrast, weight loss reduces blood pressure. Blood pressure falls by about 1 mmHg for every 2.2 pounds (1.0 kg) of weight lost, an effect that is consistent for both men and women and for people of different ethnicities. The beneficial effects of weight loss on blood pressure add to those of drug therapy and other nonpharmacologic measures, including reducing sodium intake, reducing alcohol intake, and exercise.

Added benefits of weight loss ? In addition to reducing blood pressure, weight loss has several other benefits, including a reduction of blood levels of lipids (cholesterol and related substances), a partial reversal of heart enlargement, a reduced risk of diabetes, and an improved sense of well-being and quality of life.

Maintaining weight loss ? Weight loss is difficult to maintain because it triggers metabolic changes that tend to resist weight loss. Also, some antihypertensive drugs may make it more difficult to lose weight and may actually be associated with gradual weight gain. In people with severe obesity, drug therapy may be necessary to achieve and maintain weight loss. ( See "Patient information: Therapy for obesity" ).

STUDIES OF NONPHARMACOLOGIC MEASURES FOR THE TREATMENT AND PREVENTION OF HYPERTENSION ? Several studies have evaluated the benefits of nonpharmacologic measures in people with hypertension and in people at risk for hypertension.

Treatment of hypertension ? Three large studies have assessed the role of nonpharmacologic measures in the treatment of hypertension.

Standard diet versus modified diet plus weight loss ? In one study, people who had well-controlled blood pressure when taking antihypertensive drugs discontinued these drugs. Half of the people ate a standard diet while the other half ate a lower salt diet, moderated alcohol intake, and followed a plan for weight loss. After four years, hypertension had returned in 95 percent of the people who ate the standard diet but in only 61 percent of the people who ate the modified diet and followed measures to lose weight.

Treatment of Mild Hypertension Study (TOMHS) ? In the TOMHS, a group of people with mild hypertension followed a program that entailed weight loss, reductions of dietary sodium and alcohol, and increased physical activity; this program was associated with a fall in blood pressure. Some of the people were then assigned to antihypertensive drugs, and some were assigned to a placebo. Four years later, the reductions in blood pressure were still present in the placebo group, although the reductions in blood pressure were greater in the group that took antihypertensive drugs. The results of the study also suggested that, although people were less likely to follow the initial program over time, the program still had measurable benefits four years later.

Dietary Approaches to Stop Hypertension (DASH) Trial ? In the DASH trial, people with normal or high blood pressure were assigned to one of three diets: a standard diet (a diet low in fruits and vegetables), a diet rich in fruits and vegetables, or a combination diet (a diet rich in fruits, vegetables, and low-fat dairy products, and low in saturated and total fat). Compared to the people who ate the standard diet, the people who ate the fruits and vegetables and combination diets had significant reductions in blood pressure. Blood pressure reductions were greater in the people who ate the combination diet than in the people who ate the extra fruit and vegetable diet; this difference was more pronounced in people with hypertension than in people without hypertension. The effects of the diets on blood pressure were maximal after only two weeks and were still present at eight weeks.

In a separate study, restricting dietary sodium in combination with the DASH diet produced a further reduction in blood pressure.

Prevention of hypertension ? Three large studies have assessed the role of nonpharmacologic measures in the prevention of hypertension.

Standard diet versus modified diet plus weight loss ? One study, the Trials of Hypertension Prevention, Phase I, evaluated the effects of dietary changes and weight loss in people with borderline high blood pressure. Half of the people ate a standard diet, and half of the people followed a program that included a lower sodium diet, lower alcohol intake, and measures to lose weight. After five years, 19.2 percent of the people who ate the standard diet had developed hypertension compared to only 8.8 percent of the people who followed the program.

Trials of Hypertension Prevention, Phase II ? The Trial of Hypertension Prevention, Phase II, included overweight, middle-age adults with normal blood pressure who were assigned to one of four treatments: usual medical care, a lower salt diet, a weight loss program, or combined treatment (both a lower salt diet and weight loss). After six months, the people assigned to the weight loss group and the combined treatment group had the greatest reductions of blood pressure. Although the effectiveness of these treatments decreased over time, individuals in the treatment groups were still less likely than individuals in the usual care group to have hypertension four years later.

Trial of Nonpharmacologic Interventions in the Elderly (TONE) ? The TONE study included older adults who took only one antihypertensive drug to control their blood pressure. The people were assigned to one of four treatments: usual medical care, a weight loss program, a lower sodium diet, or combined treatment (both weight loss and a lower sodium diet). All of the groups had reductions of blood pressure, but reductions were greatest in the people assigned to the combined treatment group. After 30 months, the people assigned to the treatments were less likely to have a return of hypertension, to need antihypertensive drugs, and to experience cardiovascular events.

WHERE TO GET MORE INFORMATION ? Your doctor is the best resource for finding out important information related to your particular case. Not all patients with hypertension are alike, and it is important that your situation is evaluated by someone who knows you as a whole person.

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